The present invention relates broadly to methods and apparatus for contacting liquids and gases. Such apparatus find application as evaporative coolers and cooling towers. Cooling towers are utilized for the cooling of water and within air conditioning systems. Evaporative coolers are used generally to cool and moisturize air for various applications. The cooled moisturized air produced by an evaporative cooler has been found especially useful in increasing the efficiency of gas turbines in localities where the ambient air is relatively dry and hot.
Evaporative coolers and cooling towers both operate in a similar manner. Air is forced over water which is gravitating downwardly through the apparatus in a heat exchange relationship. In both types of apparatus the water flows through a tortuous path. The tortuous path is formed by elements known as contact bodies, packing, or media elements. The media elements are usually formed of corrugated sheet material. The corrugated sheets are sandwiched together with the corrugations of adjacent sheets angled relative to one another. In this manner, a tortuous path is provided for the water in a downwardly gravitating direction.
So that the water will flow downwardly by gravity between the media elements, the media elements are arranged in a disposition in which a plane passing medially through each of the corrugated sheets lies substantially in a vertical plane. Due to this orientation, a tortuous cross air flow path is also provided.
As noted in U.S. Pat. No. 3,415,502 to Munters, issued Dec. 10, 1968, the media elements may be constructed of a wetting or absorbing material, such as fibers of cellulose or asbestos. The wetting of the media elements, however, is not intended to create water flow through the elements which is a major portion of the water flow through the cooling tower of Munters. The corrugated sheets in Munters, as is typical of prior art cooling towers and evaporative coolers, are vertically disposed and utilize a film flow of water between and over the media elements as the water flow through the apparatus. The wetting of the media elements by Munters is apparently for the purpose of aiding the film flow of the water over the elements. The contact between the air passing through the media elements of Munters is between the film of water and the air. As will be noted hereinafter, the gas to liquid contact in the present invention is not between a film flow of a liquid and a gas.
Liquid and gas contact bodies of the prior art which utilize a film flow of water have generally experienced a water carryover problem. Water carryover occurs when the water flowing over the media elements is blown out of the air output side of a contact body. Various methods have been utilized to either minimize the amount of water carryover or to stop the water carryover after it exits the contact body. In U.S. Pat. No. 3,792,841 to Munters, issued on Feb. 19, 1974, a specific disposition of the corrugated sheets is utilized to attain a uniform film flow over the sheets and to minimize the tendency of the water to be entrained with the air stream flowing through the contact body. In U.S. Pat. No. 3,917,764 to Phelps, issued on Nov. 4, 1975, a drift eliminator is disposed across the path of air exiting a contact body in order to entrap any water carryover. Since the present invention does not utilize a film flow of water, the problem of water carryover is minimized.